| 摘要 |
<p>A method and a bipolar chopper for obtaining an output voltage from an a.c. input voltage supply, by continuously sampling the a.c. input voltage so as to produce a plurality of voltage samples during each cycle of the a.c. input voltage supply, selecting a fraction of each said voltage sample commensurate with a desired fractional power consumption thereof, and low-passing filtering said fraction of each said voltage sample. According to a preferred embodiment, the output voltage is sinusoidal and, for each voltage sample, a departure of the instantaneous voltage of the respective voltage sample from the desired voltage magnitude allows a commensurate fraction of the voltage sample to be output. This produces a clean sinusoidal waveform for the output voltage and preserves near unity power factor.</p> |
